Objectives  Aiming at the increasingly compressed profit margins of the ship industry and environmental pollution caused by ship navigation, a shipboard energy management system (EMS) scheme that satisfies various constraints is proposed.

  Methods  First, a mathematical model of the EMS is established to clarify a series of constraints such as arrival time restrictions, carbon dioxide emission standards and operational constraints. Then, an improved particle swarm optimization algorithm (PSO) is used to reduce overall operating costs and greenhouse gas emissions, taking the place of real-number coding and iterative optimization of the start and stop status, operating status, sailing speed and other parameters of generator sets and diesel generator sets. Finally, taking the sailing standard data of a passenger ferry as an example, three optimization schemes are set to verify the feasibility and effectiveness of the PSO algorithm.

  Results  The results of the simulation comparison show that the operating cost of scheme 1 (the initial scheme) is 37 022.75 m.u., and the operating cost of scheme 2 (only the optimal distribution of the electric power of the generator set) is 36 993.27 m.u., a reduction of 0.079 6%. Option 3 (overall optimization) is 35 851.25 m.u., a reduction of 3.164 2%, which takes the requirements of the economy and environmental protection into account.

  Conclusions  The EMS scheme based on the improved PSO algorithm can significantly reduce operating costs, and ensure a relatively stable sailing speed and load distribution curve, which is conducive to improving the working efficiency and economic benefits of the EMS.